How do I determine the specific heat of an unknown if...?

A 100 g aluminum calorimeter contains 250 g of water. The two substances are in thermal equilibrium at 10�C. Two metallic blocks are placed in the water. One is a 50 g piece of copper at 79�C. The other sample has a m of 79 g and is originally at a temperature of 100�C. The entire system stabilizes at a final temperature of 20�C. Determine the specific heat of the unknown second sample.